1. Field of the Invention
The present invention relates to a process for producing an alkoxysilane-based compound in an industrially applicable manner, which uses a secondary alcohol or a tertiary alcohol as a raw material.
2. Description of the Prior Art
Conventionally, the most commonly known process for producing an alkoxysilane-based compound is a process in which, as shown below, an alcohol and a halogenated silicon compound are subjected to a dehydrohalogenation reaction in the presence of a tertiary amine.R—OH+ClSi(CH3)3+(C2H5)3N→R—OSi(CH3)3+(C2H5)3NH+Cl−(wherein, R represents a monovalent hydrocarbon group)
In those cases in which a primary alcohol such as methyl alcohol is used as a reaction raw material, the reaction of the above process proceeds substantially quantitatively, enabling an efficient production of the target compound.
However, in the above process, if a secondary alcohol or a tertiary alcohol is used as the reaction raw material, then the reaction rate of the above reaction slows significantly compared to the case in which a primary alcohol is used. Particularly in cases where an attempt is made to react a dichlorosilane compound with a 2-fold mol equivalent of a secondary alcohol or a tertiary alcohol to form a disubstituted product, or in cases where an attempt is made to react a trichlorosilane compound with a 3-fold mol equivalent of a secondary alcohol or a tertiary alcohol to form a trisubstituted product, an extremely long reaction time is needed, the reaction yield is poor, and because the product also contains residual unreacted raw materials, as well as partially reacted components such as monosubstituted products, the target product must be isolated by distillation, which further reduces the yield of the target compound.
On the other hand, Japanese Patent publication No. 2,688,469 discloses a process for producing a (meth)acrylic functional group-containing organosilicon compound through a dehydrohalogenation reaction of (meth)acrylic acid and a haloalkyl group-containing organosilicon compound, wherein the reaction is conducted in the presence of 1,8-diazabicyclo[5.4.0]undecene-7 (hereafter referred to as “DBU”), which functions as a hydrogen halide acceptor.
However, DBU is expensive, and the use of large quantities of DBU as an industrial raw material is undesirable from a cost perspective, and in addition, a step for isolating and recovering the DBU is necessary, using filtration to separate the salt of DBU and the hydrogen halide produced in the reaction, and then washing the isolated salt with an aqueous alkali solution, and so even from a process perspective, the use of DBU is unfavorable.